Hello all,
Thank you very much for the discussion.
Regarding Nick Cox's valuable suggested partial test (macrotest), that
and other similar tests work fine in ado-files that I create myself
from scratch, as well as others borrowed from co-workers, etc. This
problem has only occurred when attempting to modify Stata ado-files.

One other tidbit: Your original code works when version is set to 7
but not 6. Further, this code works:

Why? The whatsnew file for Stata 7 says "Stata now allows names to be
up to 32 characters long. That includes variable names, label names,
macro names, and any other name you can think of." I don't know what
the limit was in V 6 -- 7 characters maybe? -- but my_test_local was
probably too long of a name. Make your macro names shorter, like I
did above, and I think your code will work.